/*
 * Copyright (c) 2007, 2015, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
/*
 * Copyright 2001-2004 The Apache Software Foundation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * $Id: ParentPattern.java,v 1.2.4.1 2005/09/02 11:10:09 pvedula Exp $
 */

package com.sun.org.apache.xalan.internal.xsltc.compiler;

import com.sun.org.apache.bcel.internal.generic.ConstantPoolGen;
import com.sun.org.apache.bcel.internal.generic.ILOAD;
import com.sun.org.apache.bcel.internal.generic.INVOKEINTERFACE;
import com.sun.org.apache.bcel.internal.generic.ISTORE;
import com.sun.org.apache.bcel.internal.generic.InstructionHandle;
import com.sun.org.apache.bcel.internal.generic.InstructionList;
import com.sun.org.apache.bcel.internal.generic.LocalVariableGen;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ClassGenerator;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.MethodGenerator;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.TypeCheckError;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.Util;

/**
 * @author Jacek Ambroziak
 * @author Santiago Pericas-Geertsen
 */
final class ParentPattern extends RelativePathPattern {

  private final Pattern _left;
  private final RelativePathPattern _right;

  public ParentPattern(Pattern left, RelativePathPattern right) {
    (_left = left).setParent(this);
    (_right = right).setParent(this);
  }

  public void setParser(Parser parser) {
    super.setParser(parser);
    _left.setParser(parser);
    _right.setParser(parser);
  }

  public boolean isWildcard() {
    return false;
  }

  public StepPattern getKernelPattern() {
    return _right.getKernelPattern();
  }

  public void reduceKernelPattern() {
    _right.reduceKernelPattern();
  }

  public Type typeCheck(SymbolTable stable) throws TypeCheckError {
    _left.typeCheck(stable);
    return _right.typeCheck(stable);
  }

  public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
    final ConstantPoolGen cpg = classGen.getConstantPool();
    final InstructionList il = methodGen.getInstructionList();
    final LocalVariableGen local =
        methodGen.addLocalVariable2("ppt",
            Util.getJCRefType(NODE_SIG),
            null);

    final com.sun.org.apache.bcel.internal.generic.Instruction loadLocal =
        new ILOAD(local.getIndex());
    final com.sun.org.apache.bcel.internal.generic.Instruction storeLocal =
        new ISTORE(local.getIndex());

    if (_right.isWildcard()) {
      il.append(methodGen.loadDOM());
      il.append(SWAP);
    } else if (_right instanceof StepPattern) {
      il.append(DUP);
      local.setStart(il.append(storeLocal));

      _right.translate(classGen, methodGen);

      il.append(methodGen.loadDOM());
      local.setEnd(il.append(loadLocal));
    } else {
      _right.translate(classGen, methodGen);

      if (_right instanceof AncestorPattern) {
        il.append(methodGen.loadDOM());
        il.append(SWAP);
      }
    }

    final int getParent = cpg.addInterfaceMethodref(DOM_INTF,
        GET_PARENT,
        GET_PARENT_SIG);
    il.append(new INVOKEINTERFACE(getParent, 2));

    final SyntaxTreeNode p = getParent();
    if (p == null || p instanceof Instruction ||
        p instanceof TopLevelElement) {
      _left.translate(classGen, methodGen);
    } else {
      il.append(DUP);
      InstructionHandle storeInst = il.append(storeLocal);

      if (local.getStart() == null) {
        local.setStart(storeInst);
      }

      _left.translate(classGen, methodGen);

      il.append(methodGen.loadDOM());
      local.setEnd(il.append(loadLocal));
    }

    methodGen.removeLocalVariable(local);

        /*
         * If _right is an ancestor pattern, backpatch _left false
         * list to the loop that searches for more ancestors.
         */
    if (_right instanceof AncestorPattern) {
      final AncestorPattern ancestor = (AncestorPattern) _right;
      _left.backPatchFalseList(ancestor.getLoopHandle());    // clears list
    }

    _trueList.append(_right._trueList.append(_left._trueList));
    _falseList.append(_right._falseList.append(_left._falseList));
  }

  public String toString() {
    return "Parent(" + _left + ", " + _right + ')';
  }
}
